The present invention relates to irrigation equipment, and more particularly, to sprinklers of the type that use internal turbines to rotate a nozzle to distribute water over turf or other landscaping.
Many regions of the world have inadequate rainfall to support lawns, gardens and other landscaping during dry periods. Sprinklers are commonly used to distribute water over such landscaping in commercial and residential environments. The water is supplied under pressure from municipal sources, wells and storage reservoirs.
So called xe2x80x9chose endxe2x80x9d sprinklers were at one time in widespread use. As the name implies, they are devices connected to the end of a garden hose for ejecting water in a spray pattern over a lawn or garden. Fixed spray head sprinklers which are connected to an underground network of pipes have come into widespread use for watering smaller areas.
Impact drive sprinklers have been used to water landscaping over larger areas starting decades ago. They are mounted to the top of a fixed vertical pipe or riser and have a spring biased arm that oscillates about a vertical axis as a result of one end intercepting a stream of water ejected from a nozzle. The resultant torque causes the nozzle to gradually move over an adjustable arc and a reversing mechanism causes the nozzle to retrace the arc in a repetitive manner.
Rotor type sprinklers pioneered by Edwin J. Hunter of Hunter Industries, Inc. have largely supplanted impact drive sprinklers, particularly on golf courses and playing fields. Rotor type sprinklers are quieter, more reliable and distribute a more precise amount of precipitation more uniformly over a more accurately maintained sector size.
A rotor type sprinkler typically employs an extensible riser which pops up out of a fixed outer housing when water pressure is applied. The riser has a nozzle in a rotating head mounted at the upper end of the riser. The riser incorporates a turbine which drives the rotating head via a gear train reduction, reversing mechanism and arc adjustment mechanism. The turbine is typically located in the lower part of the riser and rotates about a vertical axis at relatively high spend. Some rotor type sprinklers have an arc return mechanism so that if a vandal twists the riser outside of its arc limits, it will resume oscillation between the arc limits to prevent sidewalks, people and buildings from being watered. Rotor type sprinklers used on golf courses sometimes include an ON/OFF diaphragm valve in the base thereof which is pneumatically or electrically controlled.
On occasion it would be desirable for a rotor type sprinkler to rotate its nozzle much more rapidly than during normal irrigation. For example, a higher than normal nozzle rotation speed may be desirable for dust control, washing of chemicals from turf and plants, and the protection of vegetation from near freezing or freezing conditions. A quick application of water via high speed rotation of the nozzle is an acceptable way to accomplish these beneficial results. Conventional sprinklers are typically manufactured with a predetermined rotational speed so the user is forced to buy one speed or the other.
It is therefore the primary object of the present invention to provide a rotor type sprinkler with a variable stator for changing the rotational speed of the nozzle.
It is another object of the present invention to provide a rotor type sprinkler with a user adjustable nozzle speed.
According to the present invention a sprinkler includes an outer housing having a lower end connectable to a source of pressurized water. A riser is vertically reciprocable along a vertical axis within the outer housing between extended and retracted positions when the source of pressurized water is turned ON and OFF. A nozzle is mounted at an upper end of the riser for rotation about the vertical axis. A turbine is mounted inside the riser for rotation at different speeds in response to changes in pressure of the water flowing past the turbine. A drive mechanism is mounted within the riser and connects the turbine and the nozzle for rotating the nozzle. An adjustable stator changes the pressure of the water flowing past the turbine to vary the speed of rotation of the nozzle.